The radical scavenging activity of Spilanthes acmella root extracts was determined as described by Gayatri et al.
4.3mg of DPPH (2, 2-Diphenyl -1- picrylhydrazyl) was dissolved in methanol(6.6ml) to prepare 0.3mM DPPH solution
and it was protected from light by covering the test tubes with aluminium foil.